U.S. patent application number 13/278624 was filed with the patent office on 2012-04-26 for transmitting system, receiving device, and a video transmission method.
Invention is credited to Shunichi Gondo, Yasuo Ohya, Sunao Wada.
Application Number | 20120099656 13/278624 |
Document ID | / |
Family ID | 45973019 |
Filed Date | 2012-04-26 |
United States Patent
Application |
20120099656 |
Kind Code |
A1 |
Ohya; Yasuo ; et
al. |
April 26, 2012 |
TRANSMITTING SYSTEM, RECEIVING DEVICE, AND A VIDEO TRANSMISSION
METHOD
Abstract
A stream transmitting system for transmitting a data stream,
which has first layer including base data and second layer
including data supplementing the base data, includes a transmitting
device and a receiving device. The transmitting device includes: a
transmission control unit for packetizing the data of the first
layer and the data of the second layer to output a data packet of
the first layer and a data packet of the second layer; first
transmitting unit for transmitting the data packet of the first
layer to the receiving device through first transmission path; and
second transmitting unit for transmitting the data packet of the
second layer to the receiving device through second transmission
path. The receiving device includes: first receiving units for
receiving the data packet transmitted through the first
transmission paths; and a reception control unit for reconstructing
a hierarchically-encoded data stream.
Inventors: |
Ohya; Yasuo; (Tokyo, JP)
; Wada; Sunao; (Kanagawa-ken, JP) ; Gondo;
Shunichi; (Tokyo, JP) |
Family ID: |
45973019 |
Appl. No.: |
13/278624 |
Filed: |
October 21, 2011 |
Current U.S.
Class: |
375/240.23 ;
375/240.01; 375/259; 375/E7.026; 375/E7.078 |
Current CPC
Class: |
H04N 19/30 20141101;
H04N 21/4622 20130101; H04N 19/00 20130101; H04N 21/8547 20130101;
H04N 21/234327 20130101; H04N 21/631 20130101 |
Class at
Publication: |
375/240.23 ;
375/259; 375/240.01; 375/E07.026; 375/E07.078 |
International
Class: |
H04N 7/26 20060101
H04N007/26; H04L 27/00 20060101 H04L027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 26, 2010 |
JP |
2010-240011 |
Claims
1. A transmitting system comprising: a transmission control unit
for packetizing data of a first layer and data of a second layer to
output a data packet of the first layer and a data packet of the
second layer; a first transmitting unit for transmitting the data
packet of the first layer to a receiving device through a first
transmission path; and a second transmitting unit for transmitting
the data packet of the second layer to the receiving device through
a second transmission path that is different from the first
transmission path in terms of transmission schemes; a first
receiving unit for receiving the data packet transmitted through
the first transmission path; a second receiving unit for receiving
the data packet transmitted through the second transmission path;
and a reception control unit for reconstructing a
hierarchically-encoded data stream on the basis of the data packet
received by the first receiving unit and the data packet received
by the second receiving unit.
2. The transmitting system of claim 1 wherein the first layer of
data comprises a base video signal and the reconstructed
hierarchically-encoded data stream is of higher quality than the
base layer.
3. The transmitting system of claim 2, wherein the
hierarchically-encoded data stream is constructed in a format based
on H.264/SVC (Scalable Video Coding).
4. The transmitting system of claim 3, wherein the transmission
control unit adds a time stamp, which is contained in the
hierarchically-encoded data stream, to the data packet of the first
layer and the data packet of the second layer, and the reception
control unit performs synchronization between the data of the first
layer and the data of the second layer on the basis of the time
stamp contained in the data packet received by the first receiving
unit and the second receiving unit.
5. The transmitting system of claim 2, wherein the transmission
control unit adds information for performing synchronization
between the data of the first layer and the data of the second
layer to the data packet of the second layer, and the reception
control unit performs synchronization between the data of the first
layer and the data of the second layer on the basis of the
information contained in the data packet received by the second
receiving unit.
6. The transmitting system of claim 2, wherein the second
transmitting unit transmits the data packet of the first layer,
together with the data packet of the second layer, to the receiving
device through the second transmission path.
7. The transmitting system of claim 1 wherein the first
transmission path comprises an RF transmission path and the second
transmission path comprises an IP transmission path.
8. A receiving device for connecting to a transmitting device that
packetizes data of a first layer and data of a second layer, which
constitute a hierarchically-encoded data stream, transmits a data
packet of the first layer through a first transmission path, and
transmits a data packet of the second layer through a second
transmission that is different from the first transmission path in
terms of transmission schemes, comprising: a first receiving unit
for receiving the data packet transmitted through the first
transmission path; a second receiving unit for receiving the data
packet transmitted through the second transmission path; and a
reception control unit for reconstructing a hierarchically-encoded
data stream on the basis of the data packet received by the first
receiving unit and the data packet received by the second receiving
unit.
9. The receiving device of claim 8, wherein the
hierarchically-encoded data stream is constructed in a format based
on H.264/SVC (Scalable Video Coding).
10. The receiving device of claim 8, wherein the reception control
unit performs synchronization between the data of the first layer
and the data of the second layer on the basis of a time stamp
contained in the data packet received by the first receiving unit
and the second receiving unit.
11. The receiving device of claim 8, wherein the transmitting
device adds information for performing synchronization between the
data of the first layer and the data of the second layer to the
data packet of the second layer, and the reception control unit
performs synchronization between the data of the first layer and
the data of the second layer on the basis of information for
performing synchronization between the data of the first layer and
the data of the second layer contained in the data packet received
by the second receiving unit.
12. The receiving device of claim 8, wherein the transmitting
device comprises: a transmission control unit for packetizing the
data of a first layer and data of a second layer to output a data
packet of the first layer and a data packet of the second layer; a
first transmitting unit for transmitting the data packet of the
first layer to a receiving device through the first transmission
path; and a second transmitting unit for transmitting the data
packet of the second layer to the receiving device through the
second transmission path that is different from the first
transmission path in terms of transmission schemes.
13. The receiving device of claim 8 wherein the first transmission
path comprises an RF transmission path and the second transmission
path comprises an IP transmission path.
14. A video transmission method comprising: packetizing data of a
first layer and data of a second layer of a data stream;
transmitting the data packet of the first layer to a receiving
device through a first transmission path; and transmitting the data
packet of the second layer to the receiving device through a second
transmission path that is different from the first transmission
path in terms of transmission schemes; wherein the first layer and
the second layer are operable to be reconstructed into a
hierarchically-encoded data stream by the receiving device.
15. The video transmission method of claim 14 wherein the first
layer of data comprises a base video signal and the reconstructed
hierarchically-encoded data stream is of higher quality than the
base layer.
16. The video transmission method of claim 14 wherein the
hierarchically-encoded data stream is constructed in a format based
on H.264/SVC (Scalable Video Coding).
17. The video transmission method of claim 14 further comprising:
adding a time stamp, which is contained in the
hierarchically-encoded data stream, to the data packet of the first
layer and the data packet of the second layer, and synchronizing
between the data of the first layer and the data of the second
layer on the basis of the time stamp contained in the data packet
received by the receiving device.
18. The video transmission method of claim 14 wherein the first
transmission path comprises an RF transmission path and the second
transmission path comprises an IP transmission path.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2010-240011 filed on
Oct. 26, 2010, the entire content of which are incorporated herein
by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a stream transmitting
system, a transmitting device, a receiving device, a stream
transmitting method and a stream transmitting program, which
transmit video data and audio data in streams.
BACKGROUND
[0003] With the development of digital broadcasting and the
convergence of broadcasting and communication, the development of
new services in such convergence fields has been in progress.
[0004] A conventional broadcasting transmits a variety of optimized
parameters in a frequency band of an allocated radio wave. A
broadcast transmission path is excellent in terms of a wide
coverage area and a simultaneous distribution (simultaneousness and
sameness). It is suitable for transmitting a small quantity of
contents to a very large number of receivers at the same time,
which are distributed geographically. However, since a
specification for a target receiver is predefined and it is assumed
that it will be operated over a long term, it is difficult to
drastically modify various parameters or amend a fundamental method
at a later time.
[0005] In a conventional communication, a variety of parameters are
optimized in an allowable bandwidth of a communication path prior
to transmission. A communication transmission path is excellent in
terms of locality and individuality. It is suitable for a case
where different contents are transmitted to explicit individual
terminals. Thus, a specification for a target receiver can be
individually considered, and it is relatively easy to drastically
modify various parameters or amend a fundamental method at a later
time. Further, although there is a method of realizing a wide
coverage area and a simultaneous distribution in a communication,
it is advantageous in terms of quality but is disadvantageous in
terms of scale and simultaneousness when compared to
broadcasting.
[0006] Additionally, H.264/SVC (Scalable Video Coding) has been
proposed as a technique that can dynamically change a content
transmission rate or select data streams of different parameters in
accordance with another receiver specification when communication
quality of a transmission path is degraded by a certain cause.
H.264/SVC is a technique that can previously generate and output a
plurality of data streams at the same time and obtain contents of a
desired transmission rate solely through a combination thereof.
[0007] More specifically, a plurality of data streams include a
base stream and a plurality of extension stream. A base stream is a
data stream itself of a lowest rate whereas data streams. A
plurality of data stream except for the base stream are data
streams configured as extension streams corresponding to each
difference from the base stream. These data streams are generated
in an encoding device. Thus, a transmitting device, a receiving
device or a decoding device can change a transmission rate by
merely increasing or decreasing the selection of the number of
extension streams transmitted by the transmitting device. It is
possible to obtain contents matched with a receiver specification
only if unnecessary extension streams are discarded.
[0008] However, in the conventional technique, it is assumed that
the video data is transmitted or received simply using a single
type of transmission path. Further, it is preferable that the data
streams transmitted over the broadcasting transmission path are
identical to the data streams transmitted in the existing
broadcasting in accordance with the receiver specification for the
existing broadcasting. Under these circumstances, it is very
difficult to improve playback quality using different types of
transmission paths.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram showing an entire structure of a
stream transmitting system according to an exemplary embodiment of
the present disclosure.
[0010] FIG. 2 is a block diagram showing a detailed structure of a
transmission control unit.
[0011] FIG. 3 is a block diagram showing a detailed structure of a
reception control unit.
[0012] FIG. 4 is a diagram showing an example of data stream and
data packet.
[0013] FIG. 5 is a diagram showing an example of a configuration
information table.
[0014] FIG. 6 is a flow chart showing an operation of a
transmission control device.
[0015] FIG. 7 is a diagram showing an exemplary structure of a
configuration information table.
[0016] FIG. 8 is a diagram showing an example of a method of
storing a Hash value.
[0017] FIG. 9 is a diagram showing another example of a method of
storing a Hash value.
[0018] FIG. 10 is a flow chart showing an operation of a reception
control device.
DETAILED DESCRIPTION
[0019] Hereinafter, a stream transmitting system, a transmitting
device, a receiving device, a stream transmitting method and a
stream transmitting program according to exemplary embodiments of
the present disclosure will be described in detail with reference
to the accompanying drawings.
(Configuration of Apparatus)
[0020] FIG. 1 is a block diagram showing an entire structure of a
stream transmitting system according to an exemplary embodiment of
the present disclosure. The stream transmitting system includes a
transmitting system 1 and a receiving system 2 for receiving
broadcast waves transmitted from the transmitting system 1. For
example, the transmitting system 1 is installed in a digital
broadcast transmitting station and the receiving system 2 includes
a set-top box (STB) installed in a television receiver. In the
present embodiment, as an example, it is assumed that the
transmitting system 1 performs transmission to the receiving system
2 through a broadcast transmission path (a first transmission path)
by conventional terrestrial digital broadcast waves and
transmission to the receiving system 2 through an IP communication
network (a second transmission path).
[0021] In FIG. 1, the transmitting system 1 includes a transmission
control device 10, an encoding device 30, a radio frequency (RF)
transmitting device 50, an Internet protocol (IP) transmitting
device 70 and a control unit 90. The receiving system 2 includes a
reception control device 20, a decoding device 40, an RF receiving
device 60, an IP receiving device 80 and a control unit 91.
[0022] The transmission control device 10 includes a transmission
control unit 11. The reception control device 20 includes a
reception control unit 21. The encoding device 30 includes an input
receiving unit 31 and an encoding unit 32. The decoding device 40
includes a decoding unit 41. The RF transmitting device 50 includes
an RF transmitting unit 51. The RF receiving device 60 includes an
RF receiving unit 61. The IP transmitting device 70 includes an IP
transmitting unit 71. The IP receiving device 80 includes an IP
receiving unit 81. Also, the display device 100 includes a playback
display unit 101.
[0023] FIG. 2 is a block diagram showing a detailed structure of
the transmission control unit 11 of the transmission control device
10. The transmission control unit 11 includes a data stream buffer
12, a data packet generating unit 13, a data packet buffer 14 and a
transmission determining unit 15.
[0024] FIG. 3 is a block diagram showing a detailed structure of
the reception control unit 21 of the reception control device 20.
The reception control unit 21 includes a data packet buffer 22, a
data stream reconstructing unit 23 and a data stream buffer 24.
[0025] Herein, the data stream means a stream of bits and files
including audio data and video data described in a data format used
in the input/output of the encoding device 30 and the decoding
device 40, and it includes hierarchically-encoded data. The data
packet means a stream of bits described in a data format used in
the input/output of the transmitting device and the receiving
device for the transmission path, and it is extracted from the data
stream in the shape of a packet. This will be described below in
detail.
(Connection and Operation of Respective Units)
[0026] The control unit 90 controls the transmission control device
10, the encoding device 30, the RF transmitting device 50 and the
IP transmitting device 70. The control unit 91 controls the
reception control device 20, the decoding device 40, the RF
receiving device 60 and the IP receiving device 80.
[0027] The encoding device 30 receives data through the input
receiving unit 31. Herein, an input source of the data may be any
device that can be managed by the encoding unit 32 such as a hard
disk, a network drive and a camera. The encoding unit 32 converts
data including contents received from the input receiving unit 31
into a data stream including hierarchically-encoded data. If the
data received from the input receiving unit 31 have the same format
as the data outputted from the encoding unit 32, then a process of
the encoding unit 32 may be omitted. In such a case, the
transmission control unit 11 may be configured to directly receive
the data from the input receiving unit 31.
[0028] In the transmission control device 10, the transmission
control unit 11 receives the output of the encoding unit 32 and
performs a control process for transmission. Then, the transmission
control unit 11 transmits it from the RF transmitting unit 51 of
the RF transmitting device 50 to a broadcast transmission path as
well as from the IP transmitting unit 71 of the IP transmitting
device 70 to an IP transmission network. Referring to FIG. 2, the
transmission control unit 11 receives a data stream including
hierarchically-encoded data from the encoding unit 32, stores the
received data stream in the data stream buffer 12, packetizes the
data stream in the data packet generating unit 13, and stores the
resulting data packet in the data packet buffer 14. Herein, the
transmission determining unit 15 determines an interface (RF or IP)
for transmission from the data packet buffer 14 and the timing of
the transmission. According to this determination, the data packet
is transmitted to each transmitting device.
[0029] The data packet transmitted from the RF transmitting device
50 is received through broadcast waves by the RF receiving unit 61
in the RF receiving device 60. The data packet transmitted by the
IP transmitting device 70 is received through the IP communication
network by the IP receiving unit 81 in the IP receiving device 80.
The data packet received through each of the RF receiving device 60
and the IP receiving device 80 is inputted into the reception
control unit 21 in the reception control device 20. The reception
control unit 21 performs synchronization and correlation between
data and obtains an original hierarchically-encoded data stream.
This data stream is decoded by the decoding unit 41 in the decoding
device 40, and it is displayed on a display screen of the playback
display unit 101 of the display device 100.
[0030] In FIG. 3, the reception control unit 21 in the reception
control device 20 stores the data packet received from each
receiving device in the data packet buffer 22, reconstructs the
original hierarchically-encoded data stream in the data stream
reconstructing unit 23, and stores the same in the data stream
buffer 24. The data stream stored in the data stream buffer 24 is
transmitted to the decoding unit 41. The transmitted timing and the
transmitted data amount are optional. The decoding unit 41 may be
configured to obtain the same and the control unit 91 may control
this operation.
[0031] FIG. 4 is a diagram showing an example of data stream and
data packet managed in the stream transmitting system according to
the present disclosure.
[0032] FIG. 4A shows a basic description format of a coded data
stream defined by H264/SVC (Scalable Video Coding). In FIG. 4,
"Base" denotes a base layer (a first layer) and "Ext" denotes an
extension layer (a second layer). Herein, two extension layers of
Ext(A) and Ext(B) are present. Also, reference numerals [1]-[4]
denote an index of an access unit.
[0033] FIG. 4B shows converting the data stream of FIG. 4A into an
elementary stream (i.e., an intermediate format) and classifying
the same by transmission paths. In this case, a top portion
represents data of a base layer and a bottom portion represents
data of an extension layer. "TS" contained in each elementary
stream denotes a time stamp that is given when a data stream is
converted into an elementary stream.
[0034] FIG. 4C shows packetizing a transport stream containing an
elementary stream shown in FIG. 4B into data packets. "H" denotes a
header and "Pld" denotes a payload. A top portion represents a data
packet containing data of a base layer. A bottom portion represents
a data packet containing data of an extension layer. All of the
data of the elementary stream are stored in the payload of a
transport stream packet.
[0035] FIG. 4 shows only hierarchically-encoded data, the transport
stream packet of FIG. 4C may contain other data such as videos,
audios, section information and metadata.
[0036] FIG. 5 is a diagram showing an example of a configuration
information table such as a Program Map Table (PMT), which
represents configuration information for the case where an
H.264/SVC encoding data stream is converted into data packets. The
configuration information table contains content controlled
actually by the data packet generating unit 13. The content
represents the correlation of data in the data packet, and it is
used by the reception control unit 21 when the received data packet
is reconstructed into the data stream.
(Transmission Control Process)
[0037] FIG. 6 is a flow chart showing a process of the transmission
control device 10. Herein, a description will be given of a process
of outputting a data stream received from the encoding device 30 to
the RF transmitting device 50 and the IP transmitting device 70.
The RF transmitting device 50 is a general digital broadcast
transmitting device and an input/output thereof is also pursuant to
this.
[0038] First, a data stream containing hierarchically-encoded data
is inputted from the encoding device 30 to the transmission control
device 10 (S101). The transmission control device 10 receives the
data stream and buffers the received data stream in the data stream
buffer 12 (S102). Thereafter, with reference to the data stream
buffer 12, the data packet generating unit 13 determines if the
data packet can be generated (S103). If the data packet can be
generated, then the data packet generating unit 13 extracts
necessary data from the data stream buffer 12 to generate the data
packet (S104) and buffers the generated data packet in the data
packet buffer 14 (S105).
[0039] At this time, in the data stream buffer 12, the data packet
may be buffered accompanying data representing an output
transmitting device and it may be managed in accordance with a
separate queue for each output transmitting device. The output
transmitting device of the data packet is determined by the data
packet generating unit 13. This determination may be transmitted to
the transmission control unit 11 by reading a setting file in
advance or by other means such as operator input. This is so that
it can be detected by the data packet generating unit 13.
[0040] Further, the content actually controlled by the data packet
generating unit 13 is contained in the configuration information
table. It may be carried in the data packet or may be transmitted
to other device so that the reception control device 20 can obtain
it by any other means.
[0041] FIG. 7 is a diagram showing an exemplary structure of the
configuration information table. FIGS. 7A and 7B show the case of
containing the configuration information table in a stream, while
FIG. 7C shows the case of referring to the configuration
information table outside the stream. As shown in FIG. 4C, there
are two streams (1) and (2). In FIGS. 7A to 7C, a table of a stream
(1) is a conventional broadcast scheme and only a table
representing a structure in the stream (1) is defined so that it is
established as an independent stream.
[0042] On the contrary, three variations are proposed for a table
of a stream (2). FIG. 7A shows the case of representing a structure
of an entire stream by defining only a table representing a
structure in the stream (2) in the table of the stream (2) and
referring to the table of the stream (1) and the table of the
stream (2) in combination. FIG. 7B shows the case of including a
table representing a structure of an entire stream of the streams
(1) and (2) in the table of the stream (2) so as not to refer to
the table of the stream (1). FIG. 7C shows the case of preparing an
external table and referring to a table outside the stream
independently or in combination with the table of the stream
(1).
[0043] A scheme that can store the configuration information table
in the transport stream is pursuant to a typical method. If
referring to information outside the transport stream of FIG. 7C,
then it may be stored as a file such as an XML file in a server to
obtain the same.
[0044] Since the data stream is divided into a plurality of data
packet groups for each transmission path, it is necessary to
include synchronization information for reconstruction in the
reception control unit 21.
[0045] Generally, since time stamps TS1-TS4 are given and included
in a transport stream as shown in FIG. 4B, fine grained timing
synchronization can be acquired referring to this value. However,
since the RF transmission path and the IP transmission path are
greatly different from each other in terms of transmission
conditions and delays, there may be a case where accurate
synchronization cannot be acquired solely by time stamps. Since the
RF transmitting device 50 is a typical digital broadcast
transmitting device and an input/output thereof is also pursuant to
the typical digital broadcast transmitting device, it cannot add
special information.
[0046] Accordingly, for synchronization between time stamps,
information associated with the data packet transmitted from the RF
transmitting unit 51 is stored in the data packet transmitted from
the IP transmitting unit 71. For example, a Hash value is obtained
from actual data of base layer and a time stamp of data of the base
layer, the data packet of an extension layer including the Hash
value is transmitted from IP transmitting unit 71. Thereby making
it possible to provide accurate synchronization in the reception
control unit 21.
[0047] FIGS. 8 and 9 are diagrams showing examples of a Hash value
storing method.
[0048] FIG. 8 shows an exemplary case where a Hash value is stored
as section data and separate PID data in a transport stream. In
this case, data of a Hash value relating to a data packet
containing data of a base layer of a top portion shown in FIG. 4C
becomes a single transport stream by being mixed in the transport
stream in synchronization with a data packet containing data of an
extension layer of a bottom portion shown in FIG. 4C. FIG. 9 shows
another exemplary case where a Hash value is stored as a payload or
an IP header outside a transport stream. In this case, data of a
Hash value relating to a data packet containing data of a base
layer of a top portion shown in FIG. 4C becomes a single data
packet by being mixed outside the transport stream in
synchronization with a data packet containing data of an extension
layer of a bottom portion shown in FIG. 4C.
[0049] With reference to the data packet buffer 14, the
transmission determining unit 15 determines if there is a data
packet transmitted through the RF transmitting unit 51 (S106). The
transmission determining unit 15 outputs a relevant data packet to
the RF transmitting unit 51 if a receiving side and timing
correspond thereto (S107). Likewise, with reference to the data
packet buffer 14, the transmission determining unit 15 determines
if there is a data packet transmitted through the IP transmitting
unit 71 (S108). The transmission determining unit 15 outputs a
relevant data packet to the IP transmitting unit 71 if a receiving
side and timing correspond thereto (S109). At this time, a
broadcast TS may be outputted from the RF transmitting unit 51
while an RTP may be outputted from the IP transmitting unit 71.
However, a transport protocol thereof is not limited thereto.
(Reception Control Process)
[0050] FIG. 10 is a flow chart showing an operation in the
reception control device 20. With reference to FIG. 10, a
description will be given of a process in which the reception
control device 20 outputs a data packet, which is inputted from the
RF receiving device 60 and the IP receiving device 80, to the
decoding device 40.
[0051] First, data packets containing hierarchically-encoded data
are inputted from the RF receiving device 60 and the IP receiving
device 80 (S201, S203). The reception control unit 21 stores the
data packets in the data packet buffer 22 (S202, S204). The data
stream reconstructing unit 23 obtains a configuration information
table in the data packet or by any other means and reconstructs a
data stream on the basis of the configuration information table
(S205, S206). The data stream may be synchronized because the data
stream reconstructed by using the information associated with the
data packet, which is stored in the data packet transmitted from
the transmission control unit 11 to the IP transmission path, and
the time stamps of each elementary stream.
[0052] The reconstructed data stream includes
hierarchically-encoded data. The reconstructed data stream is
buffered in the data stream buffer 24 (S207) and is outputted to
the decoding device 40 according to a request of the control unit
91 (S208, S209). Basically, the data stream inputted into the
transmission control unit 11 and the data stream outputted from the
reception control unit 21 have the same content unless there is a
data loss caused by a packet loss during transmission.
[0053] As described above, according to the above embodiment, it is
possible to absorb a difference that occurs when video data encoded
by, for example, an H.264/SVC format are transmitted using
different types of transmission paths (e.g., broadcast and
communication). Accordingly, it is possible to improve the quality
of a video played by combining received data of the communication
side while operating the conventional digital broadcast
transmitting equipment and receiver for the broadcast side.
Modified Embodiment 1
[0054] In a modified embodiment 1, the transmission of base layer
data is made to be redundancy. The IP transmitting unit 71
transmits data of a base layer transmitted by an RF side through an
IP communication network together with data of an extension layer
transmitted by an IP side. In the IP side, the data packet
generating unit 13 in the transmission control unit 11 may generate
a single data packet group based on data of a base layer and data
of an extension layer, or transmit each data packet group
separately.
[0055] Like the above embodiment, the modified embodiment 1 can
improve the quality of a video played by combining received data of
the IP side while operating the conventional broadcast wave
transmitting/receiving equipment for the RF side. Also, it is
possible to accurately play back data solely by the IP side even
when a data loss occurs due to a packet loss in the RF side.
Modified Embodiment 2
[0056] In the above embodiment, the RF transmitting device 50 is a
typical digital broadcast transmitting device and an input/output
thereof is also pursuant to the typical digital broadcast
transmitting device. However, a modified embodiment 2 can greatly
modify various parameters of the RF side or can optionally modify a
fundamental method. In this case, it is possible to store the
information associated with synchronization in the packets of the
RF transmission path and the IP transmission path. For example, the
data packet generating unit 13 in the transmission control unit 11
may store this information in a transport packet, in a stream of
transport packets like PCR, in a trailer or a header of a TS packet
like TTS and partial TS, or in a trailer or a header of an RTP
packet.
[0057] While certain embodiments have been described, these
embodiments have been presented by way of example only, and are not
intended to limit the scope of the disclosures. Indeed, the novel
methods and apparatuses described herein may be embodied in a
variety of other forms; furthermore, various omissions,
substitutions and changes in the form of the embodiments described
herein may be made without departing from the spirit of the
disclosures. The accompanying claims and their equivalents are
intended to cover such forms or modifications as would fall within
the scope and spirit of the disclosures.
* * * * *